It is an established reality that grass clippings must be removed from lawns to prevent a heavy thatch of clippings from building up which will smother new grass growth, provide a hiding place for destructive insects and provide an environment suitable for the rapid growth of mold, fungus and other lawn diseases. The removal of grass clippings has been accomplished by a variety of techniques ranging from a manual rake to an elaborate vacuum cleaning system. The manual rake functions satisfactorily for a relatively small area but when large grass tracts are groomed that method is not practical. For large tracts, tractor powered mowers are normally utilized and grass clippings are removed by relatively sophisticated vacuum or vacuum and sweeper devices.
An example of a prior art means for removing grass clippings produced by a tractor type lawn mower is presented in U.S. Pat. No. 3,903,565 on "Leaf And Grass Cart Bagger" issued to Littleberry T. Hicks on Sept. 9, 1975. This patent discloses a refuse container mounted in a small trailer adapted to be pulled by the grass mowing tractor. Clippings are transported from the cutting area to the refuse container via a ducted vacuum transport which utilizes a blower powered by some unknown means. Presumably the blower is driven by an auxiliary internal combustion engine in a manner similar to that illustrated on Page 10 of the 1976 Yard And Garden Tractors And Attachments catalog prepared by Sears, Roebuck and Company.
The use of an auxiliary internal combustion engine to drive a blower is undesirable for it tends to increase the complexity and cost of the grass clipping collection system. Furthermore it is an inefficient waste of petroleum products which is to be avoided in view of the constant threat of fossil fuel supply exhaustion.
Trailor systems such as the Hicks system discussed above are not satisfactory when mowing around flower beds and similar areas for as the tractor rounds a corner, the trailer will turn in an arc which will cause the wheels to destroy the corner portions of the flower bed or other structure which is being circumnavigated. In some instances, such as going around the corners of buildings, the tractor has to swing wide to prevent the trailing grass catcher from striking the corner of the building and thus the grass close to the building cannot be mowed.
S. E. Clarke in U.S. Pat. No. 3,203,022 on "Vacuum Cleaner For Lawns" issued Aug. 31, 1965 suggests a way to eliminate the need for an auxiliary internal combustion engine for powering the blower in a vacuum lawn sweeper. Unfortunately this system can be used only with vehicles having a rear wheel differential gear train that incorporates a power takeoff shaft. This adds significantly to the cost of the vehicle and renders the vacuum cleaner attachment a very special purpose device fabricated for a specific type of tractor and not one which is normally found in the yard and garden market. Note that the Clarke device also incorporates a separate vacuum nozzle that adds significantly to the complexity and cost of producing the device and that it further requires a wheeled dolly to support the refuse container. The shortcomings of the wheeled dolly are similar to those discussed for the wheeled cart above.